Patent GB-1087208-A (GB)
Title: Stabilization system
IPC: G09G3/04
Filed: 1965-11-09
Abstract: 1,087,208. Automatic position stabilization; fluid-pressure servomotor systems. CADILLAC GAGE CO. Nov.9, 1965 [Dec.2, 1964], No.47455/65. Headings G3P and G3R. In an arrangement for stabilizing about a fixed axis the position of a first body movable relative to a second body by means of a motor, electrical signals dependent on movements of the first body about the axis are combined with electrical signals dependent on movements of the second body about the axis to control the motor. Hydraulic power actuating system. In Fig.1 a turret-mounted gun on a tank is operated under the control of a handle 20 by hydraulic fluid from a combined motor-driven pump and reservoir 11 associated with a constant-pressure hydraulic accumulator 14. Rotation of a member 21 in one direction or the other by handle 20 actuates a valve in a block 19 to control the pressure in conduits 24, 25 so that a hydraulic motor 29 is operated to rotate the turret in a corresponding direction. The velocity of movement is arranged to be low for small movements of the handle to facilitate accurate aiming. Inward or outward movement of a member 23 by handle 20 actuates another valve in block 19 to control the pressure in conduits 42, 43 so that a hydraulic actuator 50 is operated to elevate or depress the gun. Rapid changes in elevation are effected by operation of a valve 53 controlling elevation actuator 50 through conduits 56, 57. The gun may also be elevated by means of a hand-operated pump 60, associated with a hydraulic accumulator 65, controlling the elevation actuator 50 through conduits 62, 63. A valve 31 associated with conduits 42, 43 is controlled by a plurality of switches to limit the extent of depression of the gun in different directions to prevent it fouling the tank structure. The system is also provided with various safety, relief and locking valves. Automatic stabilization. To stabilize the direction of the gun in azimuth despite tank movements, A.C. signals from the pick-off of a rateof-turn gyro mounted on the gun are demodulated, integrated and amplified to control a servo valve 26 associated with conduits 24, 25 so that the turret is rotated to maintain the gun in the desired direction. The system is further stabilized by adding to the amplifier input signals dependent on rate of turn and angular acceleration of the gun in azimuth. Stabilization is further assisted by applying to the amplifier a signal derived from a rate of turn gyro mounted on the tank so that the turret is rotated in a direction opposite to that in which the tank moves in azimuth. To permit the manual control to be effective during automatic stabilization, a signal dependent on the rotation of handle 20 or the pressure change resulting from it is also applied to the input of the amplifier in such a sense that the stabilizing system does not cancel the effect of operation of handle 20. A similar system employing two rate gyros, one on the gun and the other on the turret, is employed to stabilize elevation of the gun. Use of attitude gyros and accelerometers instead of integrating and differentiating signals from rate gyros is referred to. Automatic stabilization may be engaged or disengaged by operation of a switch associated with a delay unit controlling electromagnetically operated valves which also operate to disengage automatic stabilization in the event of electrical failure. Electric power for the stabilizing system is derived through a voltage regulator and inverter from the tank batteries. A brake associated with the turret operating motor is released electrically when the control handle is operated or when automatic stabilization is operating.